rsync exclude *2021* works but not *2020*

Question

I have this rsync command that I use for years to backup photos from my smartphone. It runs normally except if I swap --exclude *2021* to --exclude *2020*

In my real scenario, the error message is

Unexpected local arg: /media/sciuro/BCKP_WD4T/Fotos/2021/CELULAR/ If arg is a remote file/dir, prefix it with a colon (:). rsync error: syntax or usage error (code 1) at main.c(1375) [Receiver=3.1.2]

And in my test scenario, the error message is

rsync: change_dir "/home/sciuro//home/sciuro/2021" failed: No such file or directory (2) ERROR: destination must be a directory when copying more than 1 file rsync error: errors selecting input/output files, dirs (code 3) at main.c(641) [Receiver=3.1.2]

These errors only happens with --exclude *2020* independently of source and destination files/directories. Please have a look at my test scenario bellow.

Anybody can explain me what's exactly is the problem here?

The workaround was to insert the pattern between ': --exclude '*2020*'

I'm guessing that rsync has some internal 2020 or 20 encode that is being interpreted and leding to this error.

---

Real scenario

This run without error

rsync -rtpogvlHbis --ignore-existing --progress --size-only --stats rsync://localhost:6010/root/sdcard/DCIM/Camera/ /media/sciuro/BCKP_WD4T/Fotos/2020/CELULAR/ -n --exclude *2021*
receiving incremental file list
.d...p..... ./
>f+++++++++ IMG_20201228_114334605.jpg
(...)

Number of files: 78 (reg: 77, dir: 1)
Number of created files: 77 (reg: 77)
Number of deleted files: 0
Number of regular files transferred: 77
Total file size: 4,191,721,673 bytes
Total transferred file size: 4,191,721,673 bytes
Literal data: 0 bytes
Matched data: 0 bytes
File list size: 1,898
File list generation time: 0.013 seconds
File list transfer time: 0.000 seconds
Total bytes sent: 270
Total bytes received: 2,147

sent 270 bytes  received 2,147 bytes  4,834.00 bytes/sec
total size is 4,191,721,673  speedup is 1,734,266.31 (DRY RUN)

This doesn't

rsync -rtpogvlHbis --ignore-existing --progress --size-only --stats rsync://localhost:6010/root/sdcard/DCIM/Camera/ /media/sciuro/BCKP_WD4T/Fotos/2021/CELULAR/ -n --exclude *2020*
Unexpected local arg: /media/sciuro/BCKP_WD4T/Fotos/2021/CELULAR/
If arg is a remote file/dir, prefix it with a colon (:).
rsync error: syntax or usage error (code 1) at main.c(1375) [Receiver=3.1.2]

---

Test scenario

Here is a minimal test.

Origin dir and files (destination dir are empty)

sciuro@toca:~$ ls test/origin/
Captura de tela de 2020-02-10 21-48-32.png
Captura de tela de 2020-04-02 21-14-44.png
Captura de tela de 2021-01-16 13-48-26.png
Captura de tela de 2021-01-16 13-48-27.png

1° test: destination home/sciuro/2020/ + --exclude *2021*

sciuro@toca:~$ rsync -rv /home/sciuro/test/origin/ home/sciuro/2020/ --exclude *2021* -n
sending incremental file list
created directory home/sciuro/2020
./
Captura de tela de 2020-02-10 21-48-32.png
Captura de tela de 2020-04-02 21-14-44.png
    
sent 144 bytes  received 64 bytes  416.00 bytes/sec
total size is 2,443,343  speedup is 11,746.84 (DRY RUN)

2° test [FAIL]: destination home/sciuro/2021/ + --exclude *2020*

sciuro@toca:~$ rsync -rv /home/sciuro/test/origin/ home/sciuro/2021/ --exclude *2020* -n
    sending incremental file list
    rsync: change_dir "/home/sciuro//home/sciuro/2021" failed: No such file or directory (2)
    ERROR: destination must be a directory when copying more than 1 file
    rsync error: errors selecting input/output files, dirs (code 3) at main.c(641) [Receiver=3.1.2]

3° test: destination home/sciuro/2021/ + --exclude *2021*

sciuro@toca:~$ rsync -rv /home/sciuro/test/origin/ home/sciuro/2021/ --exclude *2021* -n
sending incremental file list
created directory home/sciuro/2021
./
Captura de tela de 2020-02-10 21-48-32.png
Captura de tela de 2020-04-02 21-14-44.png

sent 144 bytes  received 64 bytes  416.00 bytes/sec
total size is 2,443,343  speedup is 11,746.84 (DRY RUN)

4° test [FAIL]: destination home/sciuro/2020/ + --exclude *2020*

sciuro@toca:~$ rsync -rv /home/sciuro/test/origin/ home/sciuro/2020/ --exclude *2020* -n
sending incremental file list
rsync: change_dir "/home/sciuro//home/sciuro/2020" failed: No such file or directory (2)
ERROR: destination must be a directory when copying more than 1 file
rsync error: errors selecting input/output files, dirs (code 3) at main.c(641) [Receiver=3.1.2]

---

The workaround

 sciuro@toca:~$ rsync -rv /home/sciuro/test/origin/ home/sciuro/2021/ --exclude '*2020*' -n
    sending incremental file list
    created directory home/sciuro/2021
    ./
    Captura de tela de 2021-01-16 13-48-26.png
    Captura de tela de 2021-01-16 13-48-27.png
    
    sent 133 bytes  received 64 bytes  394.00 bytes/sec
    total size is 2,057,301  speedup is 10,443.15 (DRY RUN)

Answer 1

You need to quote the argument to --exclude, otherwise it will be expanded on the issuing host, resulting in passing local files which match that glob relative to the working directory (eg. /media/sciuro/BCKP_WD4T/Fotos/2021/CELULAR/ in your "real" scenario).

rsync -rtpogvlHbis --ignore-existing --progress --size-only --stats rsync://localhost:6010/root/sdcard/DCIM/Camera/ /media/sciuro/BCKP_WD4T/Fotos/2020/CELULAR/ -n --exclude '*2021*'